New York Mets starting pitcher Zack Wheeler delivers to the plate during Tuesday’s game against the Washington Nationals in Washington.

WASHINGTON — Zack Wheeler allowed one run in 6 2-3 innings to win his fourth consecutive decision, and Daniel Murphy’s two-run single helped the New York Mets beat the NL East-leading Washington Nationals 6-1 Tuesday.

Wheeler (7-8) gave up seven hits and allowed a run on a wild pitch, but he was good enough on a muggy night when the temperature was 85 degrees at first pitch. The righty went 3-8 with a 4.45 ERA in his first 16 starts, but is 4-0 with a 1.59 ERA in seven appearances since June 30.

When Wheeler was replaced after 109 pitches with a man on in the seventh, center fielder Juan Lagares ended the inning with a head-first diving catch of a sinking liner by Denard Span. Lagares was checked on by manager Terry Collins and a trainer but stayed in the game.

In Washington’s sixth, Jayson Werth led off with a double. When Adam LaRoche followed with a single to left, third base coach Bob Henley sent Werth home. Left fielder Eric Campbell threw out Werth with a one-hop toss; the call stood after a replay review to check whether catcher Travis d’Arnaud blocked the plate.

In the second and third, Washington accumulated three hits and four walks off Wheeler but only scored once. That was pretty much how things went for the Nationals, whose Nos. 5-6 hitters, Ian Desmond and Bryce Harper, were a combined 0 for 7 with four strikeouts and a walk.

The Mets scored a run in each of the first two innings off Gio Gonzalez (6-8), with David Wright and Wheeler delivering RBI singles. In all, Gonzalez was charged with four runs and six hits over six-plus innings.

The left-hander put two runners on to begin the seventh, and then shook his head as he walked off the mound when manager Matt Williams yanked him with Wheeler coming to the plate.

After Wheeler’s sacrifice bunt, Drew Storen hit Lagares on the left arm to load the bases.

Storen rebounded by coaxing Murphy into a potential double-play grounder to second baseman Asdrubal Cabrera. Mainly a shortstop in the majors, but flawless since changing positions when he arrived from the Cleveland Indians in a deal last week, Cabrera let the ball get under his glove to make it 4-1. Murphy was officially credited with a single.

Not much later, the sellout crowd of 40,686 began heading to the exits.

CARDINALS 3, RED SOX 2

ST. LOUIS — Jon Jay did not pick up a bat while missing five successive games with a sore wrist. Once he returned on Tuesday, the St. Louis outfielder quickly made up for lost time.

Jay hit an RBI single with two outs in the eighth inning to break a tie and lead the Cardinals to a 3-2 win over the Boston Red Sox in a battle between the two World Series teams from last fall.

“It just felt great to be back out there,” Jay said. “Even better to come through.”

The Cardinals won their third in a row and fourth in the last five. Boston has lost three in a row.

Jay blooped a hit to left off reliever Junichi Tazawa (1-3) to bring in former Red Sox A.J. Pierzynski with the winning run.

All-Star reliever Pat Neshek (5-0) picked up the win by striking out the side in the eighth.

St. Louis closer Trevor Rosenthal recorded his NL-leading 35th save in 39 chances.

“Today was a big day for us,” St. Louis manager Mike Matheny said. “There were great at-bats from everybody.”

Especially Jay.

“I didn’t swing at all until today,” Jay said. “But it feels good.”

St. Louis starter Lance Lynn gave up two runs on four hits over seven innings. Boston starter Rubby De La Rosa surrendered one run on six hits over six innings.

Pierzynski started the winning rally with a two-out hit. He was signed by the Cardinals on July 26 after being released by the Red Sox on July 16.

“Everyone wants me to say bad things about the Red Sox and I’m not going to do that,” Pierzynski said. “I’m not bitter about what happened. It just didn’t work. I don’t have one hard feeling. The only thing is I didn’t play well enough. I have nothing but respect for the organization and how they handled everything. I was proud to say I was a Red Sox.”

Oscar Taveras followed Pierzynski’s hit with a single to set the stage for Jay.

“They did a good job of putting the bat on the ball,” Boston manager John Farrell said of the Cardinals. “It seemed like Junichi had the eighth inning well in hand with two out, two strikes and nobody on. Three consecutive base hits and that was the difference.”

WHERE ARE THE CHAMPS?

Only 13 players remain from the Red Sox 25-man roster that won the World Series last fall. Through trades and attrition, the average age of the team dropped from 31 on Opening Day, to 28 on Tuesday.

KNUCKLEBALL MAN

The Red Sox have recalled knuckleball specialist Steven Wright from Triple-A Pawtucket. Wright will be making his first stint on the roster this season after four appearances last year.

WACHA ON WAY BACK

St. Louis RHP Michael Wacha began throwing on flat ground Tuesday in hopes of returning to the starting rotation in early September. He has not pitched since June 17 with a stress reaction in his right shoulder.

TRAINER’S ROOM

Red Sox: Newly acquired OF Allen Craig was placed on the 15-day disabled list with a sore ankle. He suffered the injury Friday while running to first on a ground out. OF Corey Brown was recalled from Triple-A Pawtucket and in uniform for Tuesday’s game. He was hitting .226 with 16 homers and 39 RBI. Shane Victorino underwent successful lumbar discectomy surgery in Los Angeles on Tuesday.

ON DECK

St. Louis RHP Shelby Miller (8-8, 4.14) will face close friend Joe Kelly (2-2, 4.37) in the second game of the three-game series on Wednesday. Kelly, who spent two-plus seasons with the Cardinals, will be making his first start for the Red Sox since being acquired in a trade July 31. The two served as Best Man in each other’s weddings in the off season.

“It’s going to be strange,” Kelly said. “There will be some emotions there.”